Furnace.



.No. 724,941. PATENTED APR. 7, 1903.

G. P. KENDALL.

FURNAGE.

APPLICATION rlnnn Jun 7, 1902.

no MODEL. a sums-sum 1.

Wihwopeo I PATENTBD APR. 7, 1903.

G. F. RBNDALL FURNACE.

APPLIOATIOH mum JUNE 7, 1902.

3 SHEETS-SHEET 2- KO MODEL.

alien wigs V m: Mums eva co, I'HOHJ-AHW). VIRSHJNGTCN n r- No. 724,941. PATENTED APR. 7, 1903. e. P. KENDALL.

FURNACE.

APPLICATION FILED mm 7. 1902. no MODEL. a sums-sans: s.

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m: nonms PETERS cu. PnoTp-umu. WASHINGTON, n c,

' UNITED STATES PATENT OFFICE.

cEo e FEEDEEIoK RENDALL, OF NEW YORK, Y,

IZURNACE.

SPECIFICATION forming part of Letters Patent No. 724,941,dated April 7, 1903. Application filed-Tune 7,1902. Serial No. 110,601. on man.)

To all whom it may concern:

Be it known that I, GEORGE FREDERICK RENDALL, a subject of the King of Great Britain, residing in thecity, county, and State of New York, have invented a new and useful Improvement in Furnaces, of which the following is a specification.

My lnvention consists of an improvement in a furnace, by the arrangement of which I.

am enabled-to reduce ores without adding:

any fluxes thereto at very high heats.

It further consists in-providing means, should it be desired tomake'oxids, whereby a current of oxygen is forced through said furnace andthe material produced is discharged into suitable receptacles.

It further consists of novel details of con-- tional view of another form of a furnace; thesame being taken at 00 a; as shown in Fig. 6. Fig. 6 represents a sectional view taken on line y y, Fig. 5.

Similar numerals of reference indicate corresponding parts in the figures.

Referring to the drawings, the object of my furnace is to enable me to reduce ores without any fluxes at very high heats. This I am enabled to do by preparing the ores before placing them in the closed chamber or crucible and by preventing the admission of any oxygen,and thus hindering or preventing any combustion of the material to be reduced, and at the same time obviating the danger of explosion. The high heat developed enables sulfur and phosphorus .to be vaporized and such metals as lead or zinc to be volatilized and condensed practically pure.

If it is desired or required to make oxids such as, for example, oxid of zincthe oxy-. gen is forced through the internal chamber and the material produced is collected in suitable receptacles connected with a dischargepipe at suitable intervals.

7 1 designates the casing of the furnace, the

same consisting, preferably, of the wroughtsteel or other metallic substance outerand inner tubes 2 and 3,. respectively, between which i slocated'the packing 4, of suitable non-heat-conducting material.

5 designates the base, upon which the outer and inner tubes constituting the casing of the furnace are supported, said base being sustained upon masonry or other suitable support 6. The inner portion 7 of the base is supported within the masonry by any suitable means '7 and'is recessed, as at 8, for the reception of the crucible 9, which is made of a special composition of plumbago or similar material, the crucible being provided with a recess 10, withinwhich is seated a plate or closure 11, of plumbago or similar material, which is held in position by a threaded plug '12, which latter is provided with a boss or projection 13, having holes 14 therein, whereby said plug can bescrewed in position when the parts are assembled.

The upper extremity of the crucible 9 is recessed, as at 15, for thereception of the ring 16, of plumbago or similar material, the top of said ring being seated'in a recess 17 in the lower part of the top portion 18oF the crucible or furuace proper, it being apparent that the juxtaposed ends of the portions 9 and 18 of the crucible proper meet on or about the line 20, said line 20being located within the portion 19 of the supportingeplate 21, of fireclay or other suitable material, it being noted that in the present instance said plate is of substantially the diameter of' the inner portion of, the wall 2 and that the wall 3 is preferably made of sections,between which said plate 21 is interposed. V

22 designates a recess in the upper portion of the crucible or furnace proper, within which is seated the plate 23, of p'lumbago or other similar material, said plate being held in'position by the threaded plug 24, which hasthe extension or casing 25 thereon, the

of fumes or gases from the interior of the crucible or furnace proper to the pipe 32, which is in communication with the interior of the casing 25, said pipe 32 in Fig. 1 having suitable outlets 33, at the mouth of which are secured in any suitable manner bags or receptacles 34.

35 designates a pipe which is suitably connected in Fig. 1 with an ordinary form of an injection-pump 36, said pipe 35 discharging into a nozzle or orifice 37 located in the lower portion of the furnace, whereby oxygen can be discharged into said crucible or chamber, while said valve 29, as shown in Fig. 1, is of the ordinary plain equilibrium fiat type and enables any of the furnace-gases generated internally to escape, but prevents any readmission. The means for admitting air to the burner for combustion will be understood from Figs. 1 and 6.

38 designates a suitable flue, whereby the products of combustion will be conducted from the chamber 39 to the atmosphere.

40 designates a suitable source of heat, which in the construction shown in Figs. 1 and 2 consists of an annular pipe or burner having openings in the upper portion thereof, whereby the fuel, which is preferably crude oil or gas, is introduced into the chamber 39 for the purpose of heating the walls of a crucible or furnace proper, which is composed of the members 9 and 18.

111 Fig. 2 the pipe 32 leads to the tank 41, the lower extremity of said pipe 32 having a discharge portion provided with perforations 42, which are adapted to discharge into the lower portion of said tank 41, the water-level therein being indicated by the line 43.

44 designates a pipe discharging into the nozzle or orifice 45 for the purpose of conveying a liquid hydrocarbon, if desired, in suitable quantities into the crucible.

46 designates a layer or coating of asbestos material which is situated between the plug 12 and the plate 11, and 47 designates asbestos which is situated between the lower end of the crucible 9 and the inner portion 7 of the base and plate 11, said material being adapted to permit a certain extension of the solid crucible.

In Figs. 5 and 6 I have shown a construction similar to that already described, although I have omitted the inner tube or plate 3 and the asbestos lining between the casing 2 and 3, while I have shown the crucible 48 formed without the ring 16 and the lower portion thereof being formed with a closure 49, having asbestos 50 carried thereon, and the plate 51 above the asbestos 50, the ring 52 being suitably carried by said closure and having asbestos 53 between it and the furnace 48.

In lieu of using the annular pipe 40Iemploy four burners 54, which project tangentially toward the crucible 48, which burners may be arranged either in the same plane or spirally,

as best understood from Fig. 5, whereby it will be understood that a circular motion is imparted to the flame arou nd the inner chamber or crucible. It will of course be understood, however, that, if desired, the annular pipe 40 might be so arranged as to obtain the spiral effect in the same manner. Airis supplied to the burners through suitable openings 6 in the support 6.

The operation is as follows: In carrying out the various steps of my method the ore is first carefully prepared for the furnace and all dross eliminated by'magnetic treatment, concentration,orotherwise. Afterthistreatment the ore in a finely-pulverized condition (not briqueted) is placed in the crucible composed of the portions 9 and 18, said crucible being preferably of tubular form, and the top and bottom thereof are next perfectly or hermetically closed by means of the plumbago plates 11 and 23 and the threaded closures 12 and 24, respectively, whereby any admission of oxygen is prevented. The walls of the crucible are next heated to a high degree of heat, at least to a red heat, by means of the oxyhydrogen blowpipe or other heating means 40 or 54, as will be understood from Fig. 6, Wherefrom it will be seen that the crucible is externally heated in a direct and positive manner, whereby the interior of the contents of the crucible are also heated. As I have already stated, the walls of the crucible can be made of any highly-refractory substance, providing the same is capable of withstanding the intense heat without fusing. After the crucible-walls have been heated to a sufficiently high degree of heat a liquid hydrocarbon, preferably crude petroleum, is injected by means of a force-pu mp (not shown) or a similar device into the pipe 44 in small amounts, thereby eliminating any danger from explosion. As soon as the hydrocarbon reaches the interior of the crucible it is instantly converted into a gas, which combines with the oxygen residual in the ore and crucible and passes again gradually through the relief-valve 29, which is so constructed as to be normally seated by gravity or other means, said relief-valve preventing any readmission of oxygen. An intense internal heat is thus formed, and marsh-gas ((1H,) is generated, (which is a very active reducing agent.) By the above steps and in myimproved construction of furnace any known metallic substance can be effectively reduced. Lime and carbon can be reduced to a fusible form. Phosphorus is eliminated entirely from iron or phosphate rock. Aluminium is reduced to a metal condition, as can be manganese or titanium. It is of course to be understood that the crucible relief-valve 29 can be designed any suitable size which will admit of a free escape of the gases generated, whereby there will be no danger of explosion, and as all the oxygen is eliminated in con- IIO junction with the gas found there can be no internal combustion. When the crucible has been operated a sufficient length of .time, the injection of liquid hydrocarbon into thepipe 40 is stopped, and the external heat appliedthrough the medium of the burner 39 is reduced or extinguished, as desirable, after which the bottom plate 11 of the crucible is removed andthe entire contents thereof are dumped on the furnace floor or hearth. For the reduction of metallic ores the contents is a sponge metal of great purity with a residual portion of silicon, which can be pressed or shaken out. In the reduction of iron some powdered charcoal is used on the sponge to prevent oxidation, and the entire mass is squeezed and hammered into bars of unequaled purity and softness, every particle of phosphorus, arsenic, or sulfur. having been eliminated.

In the production of aluminium and lead it is generally desirable to remelt the sponge to obtain adhesion and solidity. The oxygen,

. however, having been eliminated renders this a simple operation at the ordinary meltingheats of the respective metals.

In the production of carbid of calcium the material when reduced, which requires an approximate heat of about 3000 centigrade,

which may be varied as required, is poured in a liquid state of fusion on the furnace-hearth, where it forms an ingot.

. In the manufacture of phosphorus from ore, phosphate rock,or bone the phosphorus passes away through the relief-valve as a fume and can be condensed in water in another receptacle.

When it is desired to form oxids, more especially oxid of lead (litharge) and oxid of zinc, (zinc-white,) a supply of oxygen is forced into the interior of the crucible by means of the injection-pumps through the pipe 35 in conjunction with the oil or after the metallic ore has been converted into sponge. The oxid passes away through the relief-valve 29 and passes into the pipe 32 and through the discharge-openings 33 into the bags or receptacles 34., provided therefor. 7

I am aware that there have been many methods of externally heating furnace-walls,

crucibles, and tubular furnaces. I am also aware that furnaces are in use where oil or liquid hydrocarbon is used, generally in a blowpipe formed for the direct reduction of metals in combination with oxygen.

Particular attention is called to the use of the asbestos lining ,of the chambers, which permits of the expansion of the walls thereof for evident purposes.

As before stated, the material used in my furnace is usually of some form of plumbago or other very fusible material, which is' first compressed into sections, usually ringshaped, is tongued, grooved, or dovetailed together, or any special form of pressed brick may be used. I desire also to use upon the exterior of the internal chamber when const'ructed a coating of fused oxid of manganese and silica, or any fuse substance which is the product of an electrolytic process, such as carborundun1,in combination with any liquidconveyer. It is not essential that the silicious coating applied shall be entirely in solution, as it can be applied by a solution conveying 'the same in a more or less soluble form. This material being generally applied in liquid form, the external casingafter being erected has heat applied until the vitrified coating has formed over the entire external surface of the inner chamber, which prevents any escape of gases or vapors as created from the inside and prevents any external admission of oxygen, and in addition enables any de-' gree of heat to be used in the crucible without internal combustion of the contents.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a furnace of the kind specified, an outer casing, an inner casing, a closed chamber Within the same, means for heating the same around the lower portion thereof, and a valve within and controlling the passage between the interior of said closed chamber and the exhaust-pipe.

2. In afurnace,an outer casing,an inner casing, suitable material therebetween, a closed chamber within said inner casing, means for suitably supporting the same, and suitable material between the lower walls of said closed chamber and supporting means.

3. An improvement in a closed chamber for a furnace, which consists in forming the walls thereof of plumbago, a support for said walls asbestos between the lower edges of said Wall,

and said support for said wall, and a lining of silicious material on the interior of said furnace. I,

4. In a furnace, a closed chamber, means for heating the same, a Valve controlling. the outlet therefrom, and means for injecting oxygen thereinto.

5. In a furnace, a closed chamber, means for heating the same, a valve controlling the outlet therefrom, and means for introducing.

7 means for heating the same, a valve controlling the outlet therefrom, a discharge-pipe leading from a'point above said valve and having a plurality of discharge-outlets, and means for injectingoxygen into the lower portion of said closed chamber.

8. In a furnace, a closed chamber therein, having an outlet, a valve controlling the outlet from saidchamber, and burners adapted to heat said chamber from the exterior, said combination with a force-pump adapted to burners being arranged in substantially spiral force oxygen into said chamber as may be deform. sired.

9. In a furnace, a closed chamber having GEORGE FREDERICK KENDALL. 5 an outlet, means for heating: said chamber Witnesses:

without admitting oxygen thereto, a Valve E. B. DOW, controlling the outlet from said chamber, in J. S. CHARLESON. 

